Berkeley Researchers Identify Photosynthetic Dimmer Switch

A team of researchers has discovered the molecular "dimmer switch" that helps control the flow of solar energy in the plant's photosynthetic mechanism. The pigment-binding protein CP29, one of the "minor" light-harvesting proteins in green plants, has been identified by a group of scientists led by Graham Fleming, a physical chemist of the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California (UC) at Berkeley, as the valve that permits the critical release of excess solar energy during photosynthesis.

This study reflects how plants protect themselves from oxidation damage should they absorb too much sunlight during photosynthesis. The research group also previously identified zeaxanthin, a member of the carotenoid family of pigment molecules, as the safety outlet in the photo-protection of green plants. The researchers believe that the present discovery holds important implications for the future design of artificial photosynthesis systems that could provide the world with a sustainable and secure source of energy.

For details read the report published in Science (May 9, 2008) in a paper entitled: “Architecture of a Charge-Transfer State Regulating Light Harvesting in a Plant Antenna Protein” and the press release at: http://www.lbl.gov/Science-Articles/Archive/PBD-CP29.html